One of the rewards of doing time in a boatyard like Salt Creek Marina, in St. Petersburg, FL where Opal and I have been holed up, is the cast of intriguing characters and boats that pass through.
Earlier last month, a flatbed truck rolled in with a disassembled 40-foot performance cat that had been squeezed into a standard shipping container (roughly 40’ x 8’ x 8’). The high-tech performance cruising cat is the brainchild of Simon Angus, a boat-builder, sailor, and engineer based in Prince George, British Columbia. The sleek-looking craft is dubbed Whisper Dave, after Simon’s father. Angus’ design and manufacturing company is called Open Waters, and Whisper Dave is a prototype for a line of catamarans Open Waters hopes to produce.
In the days that followed, the hulls’ open transoms disgorged nearly all of the components required to assemble a cruising catamaran. Two weeks later, the boat was in the water. This week, Angus was putting the finishing touches on the boat before a delivery to the Eastern Caribbean this month. Aside from some unfinished bits and pieces, all that remains to be done is the installation of twin Torqeedo pod drives that will provide auxiliary propulsion.
As we saw in our review of the Bob Perry-designed Far Harbor 39, a 39-foot monohull that slid into a standard shipping container, the advantage of a boat-in-a-box are self evident to the globe trotter who wants to travel far and wide without racking up the fees and wear and tear of delivery.
Before supply chain disruption drove up shipping costs, Angus’s boat could be delivered from British Columbia to the Caribbean and be assembled for about $8-10K (actual shipping costs are much less, but I am leaving a fair margin for assembly and yard expenses). We hope to dig some more into the design features of Whisper Dave in the future, but for the moment, I’ll focus on a detail that I thought our multihull fans would appreciate—although this system would be just as practical for the monohull sailor whose mainsheet (or traveler) is out of reach from the helm.
The Manual “Dump” Line
Many of our previous reports have explored the risks of multihull capsize and dismasting, and what sailors and designers are doing to reduce this risk. Recent incidents involving high-end performance catamarans rekindled the discussion of multihull pros and cons in Practical Sailor.
One detail that we did not explore in great depth in these reports were the mechanics of a “dump line,” which allows the helmsman (or automatic system) to quickly release the mainsheet in case the boat is overpowered. Angus has a manual release system that involves the clever use of Ronstan’s constrictor textile rope clutch and allows a person at the helm to quickly release the mainsheet with the sharp tug on a parachute cord.
Many of the essential lines on the Open Waters 40 are led to the helm and through Ronstan constrictor clutches (above). As we discussed in our rope clutch test, the Ronstan’s constrictor clutches—actually woven textile tubes—work like the old paper finger traps. When the clutch is in the grip mode, the textile tube constricts and grips the line. To release the grip, a quick tug on a high-strength parachute cord opens the constrictor tube, allowing the sheet or halyard to run freely.
Angus likes the Ronstan constrictor clutches because of their simple design and because they don’t fray lines like traditional clutches can. He has also found he can “feather” the clutch to slowly ease a highly-loaded line without tearing any fibers (although it can get quite hot). Because the release mechanism is a thin parachute cord, rigging a remote release is fairly straightforward, just extend the constrictor release cord by attaching a longer cord to it. Angus used bright green parachute cord to serve as the remote release line.
The photo above depicts the dump line setup on Whisper Dave. The Ronstan constrictor clutch is located inside the boom. Angus has a cut a port in the side of the boom so that constrictor clutch is accessible. Leading through the constrictor is the actual dump line. The dump line line attaches to a swivel bullet block at the boom end that is part of the mainsheet tackle. When the clutch is released, the dump line runs freely, dropping the block and easing tension on the mainsheet. It’s important that the dump line is long enough to adequately ease the mainsheet, and that all of the hardware sized to handle anticipated loads.
A ballpark cost of the setup on Whisper Dave is about $400, but a smaller boat could set up something similar for less. Hopefully, we’ll get the chance to try out the arrangement before the boat shoves off to the Caribbean next week.